Single plate type solid-state imaging devices, such as a CMOS type solid-state imaging device and a CCD type solid-state imaging device, are known as solid-state imaging devices for imaging color images. Such a solid-state imaging device has a configuration in which a plurality of photodiodes, which are photoelectric conversion elements, are formed on a surface portion of a semiconductor substrate in the shape of a two-dimensional array, a light shielding layer is laminated thereon, and an opening allowing light to be incident on the photodiodes is provided in a place of the light shielding layer facing the photodiodes, as disclosed in JP-A-2007-180157, for example.
In many cases, color filters corresponding to three primary colors of red (R), green (G), and blue (B) are used. Moreover, for example, green (G) color filters are laminated on about half of the plurality of photodiodes formed to be arrayed in the shape of a two-dimensional array, red (R) color filters are laminated on half of the remaining photodiodes, and blue (B) color filters are laminated on the rest of the photodiodes. Thus, on a light receiving surface of each solid-state imaging device, color filters corresponding to the respective colors are arrayed as if the color filters had been distributed uniformly.
In the known solid-state imaging device described above, one light shielding layer opening corresponds to one photodiode and a color filter of one color corresponds to one light shielding layer opening. For this reason, about ⅔ of light incident on one photodiode is absorbed by a color filter (for example, blue light and green light incident on a red color filter are absorbed by the filter to become heat) which, in principle, causes a problem that the light use efficiency is low.
In addition, an optical image of a photographic subject imaged on a light receiving surface of a solid-state imaging device is sampled by each photodiode to be converted into an electric signal. In the known structure described above, however, a red sampling point, a green sampling point, and a blue sampling point are completely different. Accordingly, signal processing in which green and blue detection signals at the red sampling point are acquired by an interpolation operation of signals, which are acquired at surrounding green and blue sampling points, is required. Furthermore, there is also a problem that degradation of the quality of an imaged image caused by positional deviation of a sampling point cannot be prevented in principle.